tank silencer

[Moby Duck]

Seems like supplying a tank with what appears to be unfused ammo is a bit of a wasted exercise.
Looks like the supply vehicle is built on a tank chassis/body. It still needs engines,crew etc etc and is relatively defenceless. I am wondering how many rounds it can supply before it is empty, I suspect not very many because there is not a lot of spare room inside a tank. Seems like the design concept is wrong and the money would be better spent on supplying more tanks, then rotate empty tanks on the line with full ones.